Photoelectric Effect
What is the Photoelectric Effect? The Theory's History Albert Einstein's Nobel Prize!!! Threshold Frequency Other Vital Definitions Quantum theory: this theory and that of relativity together form the basis of modern physics. The quantum theory is necessary to be applied for situations involving small elementary type particles. Resources What is the Photoelectric Effect? The "photoelectric effect" refers to the release of powered electrons when an electromagnetic radiation shines on a metal region. In contrast to former beliefs that light does not exhibit particle-like characteristics, the photoelectric effect aids as evidence for the quantum theory in which electromagnetic waves play the role of particles. The Theory's History As members of the genre of modern physics, a majority of experiments such as the photoelectric effect are rooted to Ernest Rutherford's gold foil experiment. Rutherford's discovery of atoms' possessions of nuclei left room for the experiements to come. It therefore became common for scientists to question and test for the subliminal properties of elementary particles. Light energy as particles (the photoelectric effect) then became a question and a possibility. Although the arrival of photoelectric theories marked a strong scientific moment, there remained the question of what relationship the light held with its energy. Lenard tested and recorded that electron energy was not linear with the intensity of the incident light radiation. This left much room for what WAS linear. Albert Einstein's Nobel Prize In 1905, Albert Einstein began recording his theories concerning the wave theory of electromagnetic radiation. Stemming from his exploration of this scientific belief, came his own theory that the incident light may reacte with the electrons more spontaneously than that of waves. The wave theory entails that frequency is a major factor in the kinetic energy of electrons, and that because of each electron's own threshold frequency, lower frequencies do not produce electrons. Although this is true for continuous waves, Einstein saw that this was not the case for light. This as a quantum theory proposed that the frequency of the radiation affects the light, not the energy, of the electrons. This proposal is represented in the equation of E= hf. This is also the equation that won Albert Einstein the Nobel Prize in 1921 for his evidence that light does indeed exhibit particle-like properties. The "Magic" Called Threshold Frequency The wave theory suggests that it is mandatory for an electron to gain energy in order to move kinetically from the metal. This is a correct assumption. Einstein used photons to explain that the electrons' energy comes all together at one time. This energy is called a photon, reacting more abruptly and faster than the energy held and delivered by a wave. This, Einstein argued, is why no time passes between the arrival and departure work functions. It is as if the photon is on a jet plane from the ground state to its applied work function- a plane so fast that no time is wasted in motion. Other Vital Definitions Electronvolt: the unit which measures energy on atomic levels Photoelectron: an electron released from the surface of a metal due to the photoelectric effect. Photon: a small group of particles of electromagnetic radiation Resources http://www.physlink.com http://www.sparknotes.com/testprep http://www.journaloftheoretics.com/Articles/3-1/Pierre-final.htm